1. Field of Invention
The invention concerns a light module of a motor vehicle. The light module serves to generate a spot distribution of a high-beam-light distribution. The high-beam-light distribution is formed by a superimposition of the spot distribution and a base distribution generated by at least one other module. The invention also concerns a motor-vehicle headlight for generating a high-beam-light distribution. The headlight includes a light module designed for generating a spot distribution of the high-beam-light distribution. The high-beam-light distribution is formed by a superimposition of the spot distribution and a base distribution generated by at least one other module. Finally, the invention also concerns a headlight system for a motor vehicle including two motor-vehicle headlights disposed in a front region of the vehicle on the sides thereof.
2. Description of Related Art
Light modules of this generic type, or motor-vehicle headlights for generating high beams, with which the high beam is formed by a superimposing of a bundled spot distribution and diffuse base distribution are known from the prior art in various embodiments. An outer edge of the spot distribution becomes relatively diffused at the sides, but has a steeper incline approaching the vertical plane than does the base distribution. The base distribution has a greater range in the horizontal and vertical planes than does the spot distribution. The maximal illumination level of the spot distribution is greater than that of the base distribution. The base distribution not only illuminates a region surrounding the spot distribution in the form of a halo (light panel) with a softly diffused edge, but is also superimposed on the spot distribution and, thereby, contributes to obtaining the desired maximum illumination level in the region of the spot distribution.
The base distribution can be obtained in an arbitrary manner. From the prior art, various light modules for generating a base distribution are known. These can be designed as projection or reflection systems and may include incandescent lamps, gas-discharge lamps, semiconductor-light sources [in particular, light-emitting diodes (LEDs)], or others as the light source.
Corresponding high-beam concepts known from the prior art are, for example, as follows:
Complete High Beam from One or more Reflector Chambers without a Vertical Subdivision
A corresponding headlight with a light module for generating a typical halogen high beam can be designed as a bi-xenon headlight or light-emitting-diode (LED) headlight. The known headlight includes a light module for generating a high beam that can, for example, be designed as a reflection or projection module. The light module for generating the high beam can also be designed to generate a low-beam-light distribution—as is the case, for example, with the bi-function modules. Alternatively, the headlight can also include at least one other light module for generating a low-beam-light distribution. A high-beam module having LED light sources can be subdivided into various modules, such as different high-beam-reflector chambers, for example, wherein at least one of the modules or chambers serves to generate the spot distribution and at least one other module or chamber serves to generate the base distribution. It is, however, also conceivable that each of the chambers generates a similar individual light distribution, whereby the individual light distributions are superimposed to form the complete high beam.
Automatic High-Beam Circuitry
A camera-controlled high beam exists up to now in various steps. The simplest step is the high-beam assistant, which switches automatically from high beam to low beam upon detecting oncoming traffic without effect to the light distribution. This function has existed since 1952 and was introduced by General Motors with the name “Autronic Eye.”
Automatic Headlight-Range Control
In a module developed by Automotive Lighting for AFS (Adaptive Frontlighting System), functionality relates to a light module designed as a projection module designed to generate a variable light distribution. In particular, not only low beams and high beams can be generated, but also situation-dependent and other light distributions—such as city light, country light, highway light, dynamic-curve light, and practically any other light distribution—can be generated. The xenon bi-function module enables camera-controlled adjustment of the range or level and geometric position of the light and dark borders of a low-beam-light distribution. A control device evaluates the positions of receding or oncoming vehicles and delivers the information to the actuator control, which controls an actuator (e.g., in the form of a multiphase motor for varying the light distribution). By way of example, the geometric position of the light/dark border is then adjusted therein.
Partial High Beam
With partial high beams, a portion of the high-beam-light distribution is selectively shadowed in a xenon high-beam module. For this, moveable (in particular, flat-shutter) configurations hinged on a horizontal axis and/or screening cylindrical diaphragms shade a portion of the high beam in which other road users are detected. As a result, bright/dark zones occur in the high-beam-light distribution. The light module for generating the partially shaded partial high-beam-light distributions or headlights with the light modules are moved by a suitable actuator, or multiphase motor, in such a manner that a receding vehicle or an oncoming vehicle will lie in the region of the dark zone.
A corresponding application is, by way of example, a headlight with an AFS module having a xenon light source and shutter configuration including numerous components, which can be displaced in relation to one another in the plane of the shutter configuration by a sliding-rail guide. The shutter configuration with a sliding-rail guide is known from DE 10 2005 012 303 A1. A corresponding light module is known from, by way of example, EP 1 640 658 A2. By sliding the shutter components in relation to one another, a variable level of the horizontal light/dark border is obtained. The light module alone generates a high-beam-light distribution (i.e., the high beam is not obtained by superimposing a spot- and base-light distribution). “Bi-function” means that the light module is designed for the generation of low beams as well as high beams. The known headlights generate thereby, aside from high beams, low beams conforming to AFS in accordance with Rule 123 UN-ECE.
FIG. 1 shows, by way of example, a light distribution 10 of a partial high beam as it is generated by a headlight in a headlight system of a motor vehicle on a test screen 12 disposed at a distance from the vehicle. A horizontal plane “HH” is indicated on the test screen 12 at 0° on the vertical axis and 0° on the horizontal axis, and a vertical plane “VV” is indicated. The other headlight of the headlight system generates a mirror-image light distribution of the light distribution 10 shown therein, reflected over the vertical plane “VV.” The partial high-beam-light distribution 10 according to FIG. 1 generated by a headlight, or the corresponding light module, includes a vertical light/dark border 14 and an intersecting horizontal light/dark border 16, which runs substantially a few tenths of a degree (in particular, 0.57°) below the horizontal axis “HH.” The horizontal position of the vertical light/dark borders 14 of the partial high-beam-light distribution 10 can, by way of example, be varied by a horizontal pivoting of the respective light module or entire headlight. By superimposing a left and right partial high beam 10, shaded regions result, which have variable widths and orientations to the road space in front of the motor vehicle.
A corresponding total partial high-beam-light distribution 18 includes the partial high-beam-light distribution 10 generated by a light module of a first headlight from FIG. 1 and partial high-beam-light distribution 10′ mirror image of this from a light module of the other headlight. The total light distribution 18 has a shaded zone 20, shown in an exemplary manner in FIG. 2. The vertical light/dark border of the light distribution 10′ generated by the other headlight of the headlight system and forming a mirror image of the partial high-beam-light distribution 10 from FIG. 2 is indicated in FIG. 2 at 14′. That the headlight for generating this light distribution 18 includes one or two projection or reflection modules and each module generates a sharp vertical light/dark border 14, 14′ is characteristic thereof. For this, a partial high-beam-light distribution 10, 10′ having a vertical light/dark border 14, 14′ results thereby in each headlight.
A headlight in accordance with this may, for example, have a xenon multi-function module. The xenon multi-function module generates, aside from a low-beam-light distribution below a horizontal light/dark border, the high-beam-light distribution as a whole (i.e., not subdivided according to spot- and base-light distributions).
An LED multi-function module functions analogously to the aforementioned xenon multi-function module and also makes a vertical light/dark border available. Its dimensions, however, are relatively narrow and concentrated on the spot region of the light distribution. For this, it can generate a spot distribution for both low beams as well as for high beams. A corresponding light module is known from, for example, DE 10 2007 049 309 A1. A light distribution generated by an LED multi-function module—such as that resulting on a perpendicular test screen 30 disposed at a distance to the light module—is depicted in an exemplary manner in the upper part of FIG. 3 and indicated as a whole at 32. The vertical light/dark border is indicated at 34, and the bordering horizontal light/dark border is indicated at 36.
A special characteristic of the LED multi-function module and other concepts of this type having LEDs as light sources is the requirement of a second high beam, which supplements the spot-type high-beam-light distribution of the LED multi-function module with a lower intensity and technical demand (e.g., no vertical light/dark borders). A base distribution generated by a corresponding second high-beam module, such as that resulting on a test screen 38, is depicted in an exemplary manner in the lower part of FIG. 3 and indicated at 40. The second high-beam module for generating the base distribution can, for example, be designed as an LED projection module having a cylindrical diaphragm.
Because a single LED chip according to the state of the art emits about 250 lumen (lm), but a gas-discharge lamp emits over 3,000 lm, numerous LED chips are needed to generate the desired, or legally required, illumination value. The thermal load increases in relation to the number of chips packed closely together as well as the expenditure for establishing electrical contact to the LED chips. A module having approximately 14 to 15 closely packed chips would require a great deal of cooling at the current state of the art and, furthermore, be difficult to manage from a light-technology perspective. The known LED multi-function module from Automotive Lighting uses only four LED chips for this reason. A higher LED density is not known.
The wide supplementary high beam, or high-beam base light, necessary for generating a high beam with an LED multi-function module (cf. FIG. 3, lower part) is normally generated from a second module. The LED multi-function module generates the spot-type light distribution as the high beam for this range. The spot distribution has a vertical light/dark border as a partial high beam for oncoming traffic. The base-light module generates a semi-symmetric high-beam base light 40 as a supplement during full high-beam functionality.
Marking Lights
By an additional slit in the xenon or LED bi-function module, a single brightly illuminated vertical stripe above the low-beam light/dark border can be generated for each module. These brightly illuminated stripes may be used as so-called “marking lights” to specifically illuminate objects (people or otherwise) located and detected on the roadway or at the side thereof in front of the vehicle with an intensity similar to that of a high beam. The bright stripe has a horizontal expansion of about 1° to 3° on a perpendicular test screen disposed at a distance to the light module, or on the roadway, and extends in the vertical direction into the actual high-beam region of the light distribution. A lighting system from Automotive Lighting for generating a marking light is known from, for example, DE 20 2010 006 097. The bright stripe of the marking light is generated from a single light module or by a small, separate reflection module in the front region of the motor vehicle—for example, in the bumper.
LED Module with a Matrix-Type LED Light Source Disposed in the Form of a Matrix (Matrix Beam)
For this, a spot beam (high beam) with a relatively limited distribution (about ±15°) is subdivided into individual rectangular pixels disposed in a matrix fashion. The pixels are generated by single LEDs that are disposed in numerous lines and columns in the form of a matrix and can be individually controlled. By this, for example, a high-beam spot can be generated having discreetly modifiable light/dark borders. The LED matrix-type module generates a spot distribution of a high beam, and another arbitrary module (e.g., corresponding to the aforementioned BiG1 module) generates a base-light distribution of the high beams.
A corresponding LED matrix-type module from DE 10 2008 013 603 A1 is depicted, by way of example, in FIG. 4 and indicated as a unit at 60. An optical array 62 of the module 60 can be clearly recognized.
The optical array 62 includes a plurality of funnel-shaped lenses 64 disposed in numerous lines and columns in the form of a matrix, which bundle the light emitted by the light source. Each of the lenses 64 has at least one LED light source 66 designated thereto. The LED light sources 66 may be one LED chip or an array of numerous LED chips disposed in the form of a matrix. A light distribution 72 of the LED matrix-type module 60—as it can result on a perpendicular test screen 74 disposed at a distance to the module 60—is depicted in FIG. 5 in an exemplary manner. The individual pixels of the light distribution 72 can be clearly recognized therein. Each of the pixels is generated by one of the lenses 64. By deactivating individual LED light sources 66, non-illuminated (i.e., dark) pixels of the light distribution 72 can be generated. A light module, or a headlight, for generating a corresponding light distribution 72 is known from DE 10 2009 053 B3 as well as DE 10 2008 013 603 A1.
LED matrix-type modules having about 80 to 120 LEDs are used in pre-development projections. They are disposed in numerous lines and columns in the form of a matrix. At the cost for LEDs and circuit boards (particularly, the circuitry, control, and power-control device) as well as the cooling of the LEDs, there is a relatively high level of expenditure for the matrix-type configurations known regarding development and production. Furthermore, the known LED matrix-type modules are relatively large, which is contrary to the intention—in particular, in the front region of a motor vehicle—of reducing the space required necessary for additional aggregates and functionalities.
Various technologies have been used for some time to generate defined light distributions having horizontally and vertically limited expansions (e.g., for high-beam stripes):
The mapping with a projection system by which the LED light distribution is formed with an aperture (or a slit in an aperture).
The direct mapping of an LED or LED array with a lens. The advantage with this is the small number of parts and relatively shallow installation depth of such systems.
The mapping of an LED or LED array with a reflection system.
A motor-vehicle headlight for generating a dynamic high-beam-light distribution is known from EP 2 280 215 A2. The headlight includes numerous light modules each of which has numerous LED light sources. The light modules are disposed in the headlight in numerous lines and columns in the form of a matrix. The LEDs of a light module generate vertical and stripe-shaped segments of the high-beam-light distribution disposed at a distance to one another. The segments generated by the light modules are offset in relation to one another such that the segments of the one light module are disposed between the segments of another light module. For this, the high beam is not, however, generated by superimposing a spot light and a base light; rather, the entire high-beam-light distribution is generated by the light module. Furthermore, due to the nested configuration of the segments generated by the various modules in the high-beam-light distribution, the configuration and alignment of the individual LEDs and light modules are extensive.
A headlight is known from EP 2 085 264 A2 in which the high beam is generated by superimposing a low-beam- and high-beam-light distribution, which only illuminates a high-beam range above a light/dark border. The high-beam-light distribution does not consist, however, of a superimposition of a spot distribution and base distribution.
A vehicle headlight is known from DE 10 2008 044 968 A1 as well as DE 10 2009 020 619 A1 having an LED matrix with numerous LEDs disposed in the form of a matrix in numerous lines and rows adjacent to and on top of one another as the light source. A light distribution can be generated by the LED matrix that corresponds to the configuration of LEDs in the LED matrix subdivided in a plurality of block segments disposed in the form of a matrix. It is not specifically mentioned that the light distribution is a high-beam-light distribution. However, if the light distribution were regarded as such, then this would not be the result, at any rate, of a superimposition of a spot- and base-light distribution.
FIG. 6 shows, by way of example, a light module known from the prior art. In FIG. 6, a projection system 80 is depicted at the left and a reflection system 90 at the right. With a projection system 80, the light generated by a light source 82, or one or more LEDs, is projected through a secondary lens 84 to generate the desired light distribution in front of the vehicle. To generate a low-beam-light distribution, the edge of a shutter configuration 86 can be positioned in the focal plane of the secondary lens 84 for the beam, wherein the secondary lens 84 maps the light passing by the shutter configuration 86 and edge to form the light/dark border in front of the vehicle. The shutter configuration 86 (as shown in FIG. 6) may be aligned vertically or in any other orientation (e.g., horizontally). The light emitted by the light source(s) 82 can be bundled by a primary lens (not shown). The primary lens is, by way of example, designed as a TIR (total internal reflection) front-mounted lens of transparent material having a refractive index of n>1—such as organic or inorganic glass (in particular, PMMA or silicone). A TIR front-mounted lens bundles light passing through it by refraction at the point-of-entry surface or point-of-exit surface of the light as well as by the total reflection at peripheral edge surfaces. The secondary lens 84 (as shown in FIG. 6) may be designed as a projection lens or as a reflector (not shown). With a reflection system 90, the desired light distribution is reflected to the front of the vehicle by reflecting the light generated by the light source(s) 92 on a reflection surface 94.
Light-Forming Components
Various measures and differently designed front-mounted lenses for altering an angle aperture of a light bundle are known from the prior art. Front-mounted lenses of this type are referred to as “cross-section transformers” or “optical commutators.”
The optical commutators known from DE 102 52 228 A1 are referenced here by way of example. FIG. 7 shows FIG. 2 of DE 102 52 228 A1, and FIG. 8 shows FIG. 4b of this document, wherein the reference symbols given in FIGS. 7 and 8 relate to the document. The system described in this document is relatively compact, but offers no horizontal or vertical subdivision of the light distribution and generates either a full low beam or full high beam. A subdivision of the high beam in a spot light and base light is not mentioned. The light distribution generated herein (low beam or high beam) is formed by a projection lens (indicated at 20 in FIGS. 7 and 8).
Another example is the optic commutators known from DE 103 02 969 A1, which represent a further development of the optic commutators known from DE 102 52 228 1. In this, additional reflecting surfaces are defined in the optical commutator, which very efficiently enable an effect to be applied to the light. FIG. 9 shows FIG. 2 of DE 103 02 969 A1, and FIG. 10 shows FIG. 5b of this document, wherein the reference symbols given in FIGS. 9 and 10 refer to the document. With the system disclosed in this document, the optical commutator also serves to generate a complete light function. A subdivision of the high beam in a spot light and base light is not mentioned.
Further publications regarding optical commutators are, for example, DE 10 2005 017 528 A1, DE 10 2009 053 581 B3, DE 10 2008 013 603 A1, and DE 102 04 481 A1. Of particular interest is DE 10 2009 053 581 B3, FIG. 5 of which is shown in FIG. 11, wherein the reference symbols given in this figure refer to the document. It is proposed in this document that the optical commutator be subdivided into smaller lenses that can be combined to form a lens array. The foremost characteristic thereof is that the lens array always contains numerous lines and the individual lenses of the array have a square or rectangular surface.
Based on the prior art described, the invention should enable a camera-controlled light function that does not blind oncoming or receding vehicles, but represents for the driver a high beam in the remaining light distribution, thereby enabling an optimal illumination of the roadway and peripheral regions for the vehicle. The objective of the invention is, therefore, to propose a fully functional, simple, and cost-efficiently realizable light module for creating a spot distribution of a high-beam-light distribution.